When performing posterior cervical stabilization, the surgeon typically places screws into the lateral mass of the cervical vertebral body followed by a titanium rod and set screws. This construct provides stabilization of the cervical spine to aid in fusion of one or more levels. Occasionally, one end section of the rod is anchored to a plate attached to the occipital region in a procedure called occipitocervical stabilization. In these constructs, the rod is characterized by two sections—a first section that extends over the cervical spine and a second section that connects to the occipital plate at an angle relative to the first section. One example of an occipitocervical fixation assembly 100 is shown in FIG. 1.
Fixation assembly 100 includes a pair of spinal rods 110. Each rod 110 is inserted into a series of screw assemblies 120 configured for anchoring into a vertebral body. Each screw assembly 120 includes a bone screw 130, a rod receiver 140, and a securing element 150 for locking one of the rods 110 into the rod receiver. Each rod 110 includes a first section 110a configured to extend over the cervical vertebrae and a second section 110b configured to attach to the patient's occipital region. The second sections 110b are anchored to an occipital plate 160 having two receivers 170 and two securing elements 180. Each rod 110 is bent to form an angle between its first section 110a and second section 110b. 
In conventional occipitocervical fixation assemblies, the rod may be bent prior to placement to form the angle between the first and second sections. The pre-bent rod may be used to connect the screw or hook placed at C2 with the occipital plate. Alternatively, the screw or hook may be placed at C1 or C3. Because every patient has a different anatomy, one rod configuration will not suit all patients. Among other variables, the angle between the first and second rod sections will vary from patient to patient. Therefore, a pre-bent rod may not precisely match a patient's anatomy as the rod is placed. In many cases, the pre-bent rod requires further adjustment during placement, and must be bent intraoperatively.
Bending a rod prior to and during operation can be a time consuming and cumbersome process. In addition, bending the rod can create stress in the rod that decreases fatigue strength of the rod material. If fatigue strength is significantly reduced, the integrity of the rod can be compromised and pose a significant risk to the patient. The problems with rod bending are experienced not only with occipitocervical fixation assemblies, but are also experienced with lumbopelvic spine fixation assemblies, and other implant systems featuring elongated elements that must be manually configured to conform to specific spatial requirements.